This is a bug in the treemap only, not in the sunburst chart. To reproduce:

1. Modify one of the 2-layer treemap examples to sometimes return 0 in the valueAccessor function, such as valueAccessor={(d: Datum) => Math.random() < 0.7 ? d.exportVal as number : 0}
2. Refresh the storybook
3. You will see that the chart throws an infinite loop:

RangeError: Maximum call stack size exceeded
    at Function.get [Symbol.species] ()
    at Array.concat ()
    at push../src/chart_types/partition_chart/layout/utils/treemap.ts.__spread 

When I change the exact same chart to partitionLayout: PartitionLayout.sunburst, the chart renders.